The aim of this study was to analyze FAMEs profiles of wild Pseudomonas vesicularis strain and genetically modified P. vesicularis (pBR322) strain during phenol degradation in soil. It was found that the complete degradation of phenol at the concentration of 1.7 mg/g in soil inoculated with single strains P. vesicularis and P. vesicularis (pBR322) proceeded within 20 days. Simultaneously, no difference between their degradative activity and survival of inoculants in soil was observed. Under phenol exposure significant alterations in FAMEs profiles of both strains inoculated into contaminated soil were connected with the content of saturated fatty acids. Their percentages increased significantly when 76-91% of the initial dose of phenol was removed. Other noticeable change included the increase of cyclopropane fatty acid 19:0cy ω8c content during phenol elimination from soil.